The bag support structure of most known containers of the above type consist of peripherally spaced side beams which extend between top and bottom panels of the container for the purpose of minimising transverse bulging of the container bag wall in use.
The top and bottom panels of the various containers are made from a flexible material which could be that from which the container bag is made, a corrugated cardboard, timber, plastic or metal.
The container side beams are made from corrugated cardboard which is formed into side wall support panels or elongated posts, timber panels, plastic or metal posts and the like.
Typical intermediate bulk containers of the above type are disclosed in the specifications of the following patents: U.S. Pat. No. 6,113,270, and U.S. Pat. No. 5,025,925.
Problems associated with all known containers of the above types, other than perhaps those of the rigid box type, are that:    (a) the containers are difficult to stack and when stacked result in an unstable stack structure. This is principally due to the flexibility of the container bags and the fluid nature of their contents which they generally contain,    (b) a further difficulty with the stacking of these containers, particularly when they are filled with a high density material such as granular fertilizer, liquids and so on, is, if they are at all stackable, that the vertical load of the upper containers in the stack is transferred directly through the material in the container bags to the lower containers in the stack. This vertical load transmission could in many cases exceed the hoop strength of the reinforcing side beams and the flexible bag material between them to destroy the lower containers in the stack unless the materials from which the container components are made are expensively over-designed compared to what would be required in a single free standing container. Normally, to avoid this problem, the containers are stacked in stacks having a low vertical height with this necessitating large areas of warehouse store space in which the containers are to be stored. This becomes a highly expensive problem when the containers contain processed fresh produce which is stored and frozen in suitably insulated and refrigerated storage facilities. Additionally, it would certainly be unwise to attempt to convey, by means of a forklift or the like, even two of the containers which are stacked one on the other without the provision of at least some form of side support for the containers on the forklift tines, and    (c) the containers for various products are generally designed by variation of their bag material and the circumferential spacing between and the nature of the side beams, to be specific to a designated load material having a specific density. This problem makes it necessary for the organisation which fills the container bags with various materials to expensively keep in stock container types suited to the transportation and storage of the various materials.